Domestic violence is a problem of major proportions in the United States. The majority of studies pertaining to the etiology of domestic violence have focused on psychosocial parameters with little emphasis on biological factors. We analyzed data obtained from PET imagining and found that perpetrators of domestic violence have decreased glucose metabolism in the hypothalamus compared to controls. Perpetrators also showed decreased correlations in glucose metabolism between several cortical and subcortical structures and the amygdala. These data are currently in press and support our hypothesis that some perpetrators of domestic violence have abnormalities in the structures and pathways that control the expression of fear-induced aggression. We have now begun to analyze the DSM-IIIR diagnoses that characterize the perpetrators of domestic violence. This will enable us to ascertain if there are differences in the psychopathology between perpetrators of domestic violence with and without a diagnosis of alcohol dependence, and if these psychiatric diagnoses can provide insight into the etiological factors that may contribute to domestic violence.